Left to right:
Michael Garibaldi -- Station security chief
Susan Ivanova -- Second in Command, generally head of all the fiddly bits of running the station while Sinclair was Commandering
Londo Mollari -- Centauri Ambassador.
Delenn -- Minbari Ambassador.
Jeffery Sinclair -- Station Commander.
Talia Winters -- Psi Corps licensed telepath. There partially as the Corps representative and partially for commercial use when people have need to rent a telepath for reasons.
G'Kar -- Narn Ambassador
Dr Stephen Franklin -- station doctor.
Additional cast (because the ensemble photos I found with any of them had spoilers):
Vir Cotto -- Londo's assistant. Usually worried about something.
Na'Toth -- G'Kar's assistant. Natural habitat: skulking in shadows even if the scene is fully lit.
Lennier -- Delenn's assistant. Wishes he could still send people to the Cornfield.
Kosh -- Vorlon Ambassador. Mysteeeeeerious.